Adding water to whisky: let’s get it right

18 January 2018 by Felipe Schrieberg

While whisky nuts obsess over every tiny detail of the production of their favourite dram, they typically devote very little attention to the water they add to it. That’s a big mistake, says Felipe Schrieberg.

Which water?: Mineral content and acidity levels can create a very different taste (Photo: Taro Taylor)

We whisky geeks are an obsessive lot, ever-hungry for news and information about our favourite tipples. Maturation, differences in distillation processes, types of barley and grains sourced... All these factors, and plenty more, determine the flavours that grace the whiskies we enjoy.

Yet one very basic factor stays constant: when drinking the water of life, we are often actively encouraged to add water to whisky after we first try it neat. Water adds new flavours and textures by releasing compounds and oils in the whisky that at first are hard to detect. In fact, researchers have recently gone further, even claiming that whisky is at its tastiest with water added.

However, by adding that water we are subtly altering the taste beyond simply releasing that ‘something’ already in the whisky. All drinkable water contains combinations of minerals with distinct flavours – and that inevitably can affect our whisky in various ways and to varying degrees.

Therefore, we should take our choice of water seriously: I firmly believe that the whisky tasting experience can be compromised through a poor choice of water.

I’ll use as an example the global Evian bottle brand, one that I have seen handed out at whisky events quite regularly. Compared to other water that I’ve tried, it’s not one I enjoy. It has an astringent taste that I find unpleasant.

I found the answer to this when looking at the bottle’s label, which almost always describes the mineral content of the water. The level of bicarbonates was at 360 milligrams per litre (mg/l), a fairly high amount compared to other brands. Other waters that I’ve tried with similar bicarbonate levels also share that astringency.

For me, having Evian at a whisky tasting is a bit like being offered Heinz tomato ketchup to slather on Kobe beef. The steak will still be delicious, but you’d expect a bit more class from the condiment.

Large amounts of other minerals can also result in quite strong flavours. As I see it, water that is to be added to whisky should be as neutral as possible in taste – so water with low mineral content should be used when possible for events and tastings.

In her 2014 book Whisk(e)y Distilled, Heather Greene notes that most distilleries aim to use ‘soft’ water, containing fewer minerals, and will treat ‘hard’ water with a higher mineral content (usually magnesium and calcium) so that it becomes softer for distillation. Whisky event organisers should aim for equivalent standards.

Easy does it: Using the wrong water could ruin your experience, says Felipe Schrieberg

So, what should these standards be, and what should we as whisky (and water) consumers watch out for? Here’s what I think:

1. Read the label. I personally avoid anything with more than 150mg/l of bicarbonates (HCO3, can be astringent), 75mg/l of calcium (Ca, makes it a bit sour), 75mg/l of sodium (Na, salty), or 75mg/l of chlorides (Cl, also salty, as chloride is an ion that bonds with other minerals to create salt compounds). Other minerals, such as magnesium and various sulphates, can also appear, but I can’t say I’ve had water where these are present in high enough quantities to be able to have an opinion about their taste. Generally, I would play it safe at less than 50mg/l for anything else.

2. Aim for a water below a total of 300-400mg/l of minerals, while keeping an eye on those individual thresholds in point one above.

3. Water with an acidity of 6.4-7.5 pH tends to have the most neutral taste.

4. Distilled water, without any minerals, is a great choice and to me the ideal answer to accompany your whisky. However, it’s a specialised product, tastes unpleasant on its own and is dangerous in high volumes.

5. Avoid using bottled water if possible. Especially in Scotland, tap water often tastes better.

Do feel free to find out for yourself. Buy four or five different water brands that are varied in their mineral content, and add each to a separate glass containing the same whisky (preferably something light and delicate for the purposes of the experiment, in my opinion). I guarantee that you will taste a difference between some of them.

Keep in mind that this advice is based solely on my personal experience and judgement – a whisky-water focus group of one, and I am no water sommelier (and yes, that’s a thing).

Others will probably have different, and perhaps more qualified, views. However, I do hope that this serves as a good place to start thinking about the H2O you add to your water of life, and to help create a refreshing and delicious experience for you and those with whom you share a dram.